Manufacture of improved asphalts



Nov. 7, 1939. R. E BURK ET AL "2.179.208

MANUFACTURE OF IMPROVED ASPHALTS Filed NOV. 25, 1936 Resia/aufn Oxygen patented Nov. 7, 1939 UNITED STATES PATENT OFFICE MANUFACTURE 0F IMPROVED ASPHALTS Application November 23, 1936, Serial No. 112,348

5 Claims.

lin manufacturing asphalt, it has been the custom to blow the petroleum residuum with air, and maintain the temperature at about 30G-500 F. The procedure is very tedious, requiring a long duration of action in order to bring the material to useable characteristics of high melting point and loW penetration. Although enormous quantities of oxygen are brought into relation with the hydrocarbon material, there is not a great increase in the oxygen content, and the action is largely a dehydrogenation and conjoining of hydrocarbon molecules. We have now found that particularly eifective action in thickening up the material to desirable penetration r and melting point can be obtained Without the of but a few of the various ways in which the principle of the invention may be employed.

In said annexed drawing the sole figure is a diagrammatic showing on the order of a process flow sheet.

The stock to be worked up, a heavy petroleum oil residue,'which We designate the residuum, is in accordance with the invention heated with air and a small or catalytic amount of a polymerizing catalyst. The temperature of treatment may be 225-450 F. Desirably, the material is suitably stirred or agitated. The time of treatment is short, as for instance 20 to 300 minutes, e. g., minutes with 5 per cent FeCla at 260-280" F. As catalysts, we may employ a small amount of acid, as for instance chloro-sulphonic, phosphoric, iiuoboric, hydrochloric, nitric or sulphuric acids, and halides, as ferrie chloride, aluminum bromide, chloride, iodide, halides similarly of copper, tin, zinc, antimony,' arsenic, titanium, etc., hydroxides of sodium, potassium, etc., calcium oxide, sodium carbonate, metallic sodium, nitrogen bases, ozonides in minute amounts and peroxides in minute amounts. Particularly desirable catalysts are the acid acting catalysts, as sulphuric acid, ferric chloride. halides of aluminum, copper, tin, zinc, antimony, arsenic, titanium, boron fluoride, chlorsulphonic,

(Cl. 19d-74) phosphoric, fluoboric, hydrochloric, nitric acids, etc.

In some instances, it is desirable to subject the petroleum residuum first to an air-blowing, maintaining the temperature at about 450 F. for 5 about 600 minutes, the material being agitated by the injected air or other suitable means, and then theair-blowing is discontinued and the polymerizing catalyst is incorporated, e. g., 0.5 per cent AlCla at a temperature of about 250 F. 10 and the heating is maintained at 3D0-400 F. for 20 to 30 minutes. Such air-blowing stage can be operated to some desired penetration standard, as for instance 92 penetration at 77 F., and then the polymerization treatment is apu plied.

As an example: A petroleum residuum having initially a penetration of 200 at '77 F., is heated with 1.5 per cent of ferrie chloride at a temperature of 350 F., for 60 minutes. The product has 20 a peneration of at 77 F. and ductility l0 at 39 F. and 72.5 at '17 F.

As another example: Similar petroleum residuum is air-blown at a temperature of about 450 F. for about 12 hours, and this material is 2.a then heated with 0.5 per cent of sulphuric acid at 350 F. for 30 minutes. The product has a melting point of 137.5, ductility at 39 F. 3.5, ductility at 77 F. 29, penetration at 32 F. 17, penetration at 77 F. 44, penetration at 115 F. 30 155, and susceptibility coefficient 3.1 (the susceptibility coeiiicient indicates the ratio of penetration at different temperatures, viz., S equals the penetration at 115 minus the penetration at 32 over the penetration at '77).

As another example: A petroleum residuum is similarly air-blown iirst, and then is heated with 0.9 per cent of boron fluoride in a BFa-ether mixture at a temperature of 400 F. for 15 minutes., The product has a melting point of 140 F., duc- 40 tility at 38 F. 4, and at '17 F. 21,- penetration at 32 F. 19, and at '77 F. 47, and at 115 F. 146,

Y and a susceptibility coefficient of 2.7.

As another example: The petroleum residuum is similarly rst air-blown as above, and then is 45 heated with 0.5 per cent of FeCla at 400 F. for 30 minutes. The product has a melting point of F., ductility at 39 F. 4, and at '17 F. 30, penetration at 32 F. 17, and at 77 F. 51, and at 115 F. 192, and susceptibility factor 3.4.

Asphalts produced according to the present invention have particularly'shiny black surfaces, and are not buttery or short in consistency as has been the characteristic of asphalts from blended stocks. They also have higher melting 55 points at agiven penetration, at say '17 F., than a customary asphalt, and better susceptibility coeicients.

Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following claims, or the equivalent of such, be employed.

We therefore particularly point out and distinctly claim as our invention:

1. A process of making asphalt, which comprises air-blowing a petroleum residuum in the absence of an added catalyst while maintaining the temperature at 30G-500 F., for one to thirty or more hours, then heating the material at a temperature at least 300 F. with a small amount of a polymerizlng catalyst.

2. A process of making asphalt, which comprises air-blowing a petroleum residuum in the absence of an added catalyst While maintaining the temperature at 30o-500 F., for one to thirty or more hours, then heating the material at a temperature at least 300 F. with a small amount of an acid-acting catalyst.

3. A process of making asphalt, which comprises air-blowing a petroleum residuum in the absence of an added catalyst while maintaining the temperature at 30D-500 F., for one to thirty or more hours, then heating the material at a temperature at least 300 F. with a catalyic amount of sulphuric acid. 4. A process of making asphalt, which comprises air-blowing a petroleum residuum in the absence of an'added catalyst while maintaining the temperature at 300-500" F., for one to thirty or more hours, then heating the material with a catalytic amount of boron fluoride.

5. A process of making asphalt, which comprises air-blowing a petroleum residuum in the absence of an added catalyst while maintaining the temperature at 300-500" F., for one to thirty or more hours, then heating the material with a catalytic amount of ferric chloride.

ROBERT E. BURK. CHARLES H. WHITACRE. 

